It sounds like you want to update your analog output channels with a new value or an entire waveform every time you get a trigger signal. It's great that you're already familiar with counters creating retriggerable pulses, because you can use them for the analog output operation.
The analog output channels get updated based on the edges of the update clock. You can use the counters to supply an external update clock. So, if you set up a counter for retriggerable pulse generation, it waits for a trigger signal. When it receives it, it generates a pulse, which you have wired to the analog output update clock. When the analog circuitry sees that edge, the data will be output to the channels.
I answered a similar question regarding this for the posting "About trigger config". However, I realize that the user had originally posted in the LabVIEW General category, so it doesn't show here. Search the Developer Exchange for "retrigger analog", and you will find it. It discusses this idea as well as attaches a few examples that are currently going through a process of review to eventually be available on the web. There might be some other helpful postings as well.
Another good resource for triggering in general is the NI Developer Zone "Tips and Techniques in DAQ Triggering" document. You can find it by going to the http://www.ni.com/support pages and searching for "daq triggering".
Geneva L. Applications Engineer National Instruments http://www.ni.com/ask